Rationale behind `aria-hidden="true"` on the navdrawer element by default?

I ran into an issue earlier today where users of my application using NVDA and Apple's VoiceOver were unable to see my application's navdrawer. After investigating, it appears this is due to the `aria-hidden="true"` attribute set by default on the entire navdrawer.

Looking through the JS that controls the navdrawer, I'm not finding anything that unsets this value when the navdrawer is visible. To many screen readers, this appears to make the entire navdrawer literally invisible and inaccessible.

I'm curious what the rationale behind this decision was, and if it's supposed to be fixed somewhere that I'm not seeing. If there's no purpose for it to exist there, maybe it can be removed from the main documentation?